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There have been 2 images uploaded to this topic. View topic dwtasheet gallery. I have a reset problem with my BSD. I went through the list of things to check and do at pinwiki. Also, inspected the board visually to check for broken or cracked solder joins. I then reinstalled the original power board and the reset was back. Then by incident I pushed the U5 and the game made a reset.
I pushed it again and yet another reset. Reinstalled PB but again it would reset during game and when Datashdet pushed U5.
Took out the board again and installed a new 74LSN but still the game will reset when played and when I push U5 by hand. So I guess that it was not the IC itself that caused the problem — but what then?!?
5 X SN74LS 20pin DIP IC (74LSN SN74LSN 74LS)
What is the most likely problem to look for in this situation? Just to make sure, I dipped the board in holy water and threw in a couple of garlics under the play field. This may be your magic bullet: I tend to think that it’s a bit like fixing a flat tire by filling it with foam. It will get you running again, but who can tell with what possible side effects?
The game was build to run without the “adapter” so I like to fix the root cause rather than fixing the problem itself. Will take some time but nice to have something to dig into. I’m still interested in knowing if any of you have any experience with a game resetting as result of touching the U5 IC? Of course, I highly recommend going through pinwiki’s breakdown of the WPC reset problem: However, if you just want to get your game up and running again, Kahr’s board is the easiest way to go.
The kahr board I would only use in a pinch to keep a game going for whatever reason. It doesn’t ‘fix’ anything, just provides a work-around. Here is a Readers Digest version of what would be the main culprits in order or probability. If you start changing out components you can easily compromise plated through holes and may even make the problem worse or make the game not even boot-up. If you have a game with a Z-connector between J and J, that can be an issue too.
Best to change both the header pins and connectors. If you reseat these connectors and the game seems to magically appear to be fine. It’s just a matter of time before the resets come back, but it lets you know it’s a connector issue. That would be the next area to tackle. Be careful with C5 as it’s a snap-cap and removing it can compromise the plated through hole to BR2.
If after doing above you are still running low, I’d look at the ezsbc LM voltage regulator linked by lyonsden above. It has an adjustable pot to adjust the voltage output adds resistance between the case and ground but already comes preset at 5V. It’s nice because it produces no heat.
BR2 would be the last thing I’d change. Again be careful as to not compromise the plated through holes. Turns out that the two nuts holding the LM attached to the heat sink had loosened itself. So whenever the knocker was fired, the force of the punch into the back box would be strong enough to “mess up” the 5V signal and the watch dog would kick in. Finding this error was no easy task.
The casualties includes hours of work and input from a skilled pin-freak, two bridge rectifiers, two 15K capacitors, a tip 36, a tipa 74LS and a bypass capacitor. I’ll skip the background story and simply say – if you ever find your pinball machine reset as a result of the knocker getting powered, you should include testing if the LM is firmly connected to the heat sink.
You don’t want to force the top and bottom pads to separate from the feed through channel. Don’t know what to think about this. The simple truth about WPC is power supply loading was only marginally considered when the platform was first designed and was not reconsidered with each title released. Like so many other design elements of the time, cost and speed to market were the primary drivers. The 12v digital has a trivially light load whereas the 5 volt supply is pretty much maxed out even with brand new components.
If you are unlucky enough to have such a pairing resets are a certainty over time. My daughterboard intentionally implements a carefully thought out system-level redesign that simultaneously addresses all of these concerns. It reduces the loading on the 5 volt circuit by moving the MPU load to the 12 volt line. This reduces stresses i. It’s power is sourced from a line with plenty of spare capacity analysis on my weblink above with huge “head-room” 12v is derived from 18v and shared with peer circuitry that is not sensitive to precise voltage levels lamp columns.
It is built using a high efficiency switching regulator that minimally loads the 12 volt line beyond the actual load introduced by the MPU itself.
Reset problem – again…
While I’m not trying to be argumentative, datassheet truly is a workaround in every meaning of the word as it in no way addresses any of the underlying issues which caused the reboot, these issues will likely still exist 74ls374 after the system no longer reboots.
Under the most extreme ends of the rated tolerance spectrum the LM will supply 4. In a worst case scenario, having a voltage.
Ref the data sheet for the K – http: Wide range of the lm listed in TI data sheet. Ref the data sheet for the under voltage detector – http: If you’ve got a bottom-of-range and a top-of-rangeyour separation between supply drive and reset trigger is only 0. That lack of operating space in the design is part of the design flaw. A few more windings on on the transformer would have helped headroom part of the design flaw upstream of the regulator.
Net-net, no deception and really quite accurate And again, when thinking broader than just about the 5 volt line the daughterboard does great things for the system! BTW, I’ve been working with ezSBC for over three years now and every daughterboard I’ve ever made dataasheet one of their regulators integrated well, except the one hand-etched prototype in my basement that has a muRata regulator.
Their PSU5 exists because I asked them to create it. I’m pretty confident I was the first one to point it out to Pinside ref https: Even though the adjustment range is tighter now I still hate that microscopic adjuster I still offer the option to buy the daughterboard with one of their replacement regulators because the improved regulation efficiency counterbalances the load MPU load introduced to the 12 volt line.
All for the good of pinball.
Too bad Pinwiki hasn’t kept pace with these contemporary best practices – it still lists the cut-a-trace and install a resistor method to up your voltage I don’t know many people who would prefer datasueet find that over a daughterboard and a PSU5 behind the backglass. All specs in that datasheet are irrelevant though as neither one was used in the power driver board.
I do see where the confusion is though as Mouser sends you to this spec sheet for the LMK. I did notice that the regulator you use in your board was made by the same company that makes the fatasheet replacement part also makes the regulator 74ls374 you are using. I did not know about your involvement in thier creation. Like I mentioned 74ls37n, this is a viable option for a large number of folks to get thier machines running.
Thanks for your engineering support to the community. This is very well said. I was going to reply with something similar, but you’ve stated it perfectly except for the typo calling the LMK an LM I think the point that Rkahr 74ls74n is still valid. The standard part can range from 4. These would trigger at worst case of 4. A simple ground bounce occurance on a nearby IC can easily trigger the reset generator. Anyway – what you guys are discussing are out of my knowledge area. All I tried to say, was, that if the game was build and used to work without the “workaround” – then with my limited knowledge – I would assume that it should be fixable without this device installed.
And that is also the dayasheet I made when I finally found and fixed the problem. I have been an amusement route tech for a very long time. I just want to add a last resort dztasheet first resort if you don’t have the time to screw around with this problem fix for this reset problem.
Yes its a hack but its cheap, quick and won’t damage anything. Take out the LM you don’t need it. Get a old school video game switching power supply. We always used to have one in the service truck. Peter chow anyone lol? Solider a wire from the power supply ground to the LM ground. All you have to do now is run AC to the switching power supply and adjust the voltage. You can plug it right datasheer the service outlet if you want to keep it super simple, the CPU would still run if you switch the pinball off though.
I would consider this a quick temporary fix but you can run it this way indefinitely. Rickd 7l4s374n first post! Now help me with my reset issues on my WhiteStar board!